[PATCH v2 18/20] ocfs2_dentry_revalidate(): use stable parent inode and name passed by caller

Al Viro
2025-01-16T05:23:21Z

theoretically, ->d_name use in there is a UAF, but only if you are messing with
tracepoints...

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/ocfs2/dcache.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c
index ecb1ce6301c4..1873bbbb7e5b 100644
--- a/fs/ocfs2/dcache.c
+++ b/fs/ocfs2/dcache.c
@@ -45,8 +45,7 @@ static int ocfs2_dentry_revalidate(struct inode *dir, const struct qstr *name,
inode = d_inode(dentry);
osb = OCFS2_SB(dentry->d_sb);

- trace_ocfs2_dentry_revalidate(dentry, dentry->d_name.len,
- dentry->d_name.name);
+ trace_ocfs2_dentry_revalidate(dentry, name->len, name->name);

/* For a negative dentry -
* check the generation number of the parent and compare with the
@@ -54,12 +53,8 @@ static int ocfs2_dentry_revalidate(struct inode *dir, const struct qstr *name,
*/
if (inode == NULL) {
unsigned long gen = (unsigned long) dentry->d_fsdata;
- unsigned long pgen;
- spin_lock(&dentry->d_lock);
- pgen = OCFS2_I(d_inode(dentry->d_parent))->ip_dir_lock_gen;
- spin_unlock(&dentry->d_lock);
- trace_ocfs2_dentry_revalidate_negative(dentry->d_name.len,
- dentry->d_name.name,
+ unsigned long pgen = OCFS2_I(dir)->ip_dir_lock_gen;
+ trace_ocfs2_dentry_revalidate_negative(name->len, name->name,
pgen, gen);
if (gen != pgen)
goto bail;
--
2.39.5